Process of chain manufacture



July 1, 1930. R. w.` DULL PROCESS OF CHAIN MANUFACTURE Filed May4 7,1924 3 Sheets-Sheet l AttOWQ/yJS.

July l, 1930.

Rl w. DU| L PROCESS OF CHAIN MANUFACTURE 3 Sheets-Shet 3 Filed May '7,1924 Patented July 1, 1930 .narran stares e intern rar-ENT oFfFicr;

RAYMOND W. DULL, OF CHICAGO, ILLINOIS, ASSIGNOR TO LINK-BELT COMPANY, OF

CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS Pizocnss or cnamMenusncrunn Application led May 7; 1924. Serial No. 711,533.

My invention relates to a process of making chain from a strip of sheetmetal stock, and particularly to a process of continuously making thelinks and automatically assembling the links as they are made into thecompleted chain. The general object oi' my invention is to producechainot the type herein described; in lwhich hook and vpintle tonguesare stamped from the center 1o of the link blank and the hook and pintleend bars are bent to producea chain7 each link of Which consists of flatside bars, a relatively cylindrical hook at one end and a pintle at theother end, shaped'for rotation Within the hook of the link nextadjacent. One object is to provide a process for manufacturing chain ofthe type described, with maximum cheapness and simplicity. Anotherobject is to provide a process for the production of such chain in Whichthe hook and pintle tongues are stamped from the center of the blank andcurled into tinished hooks and pintles with a -minimum strain upon themetal of the blank and a minimum weakening and distortion of the fibersof the metal. Another object is the provision of a process of scoring orindenting the individual blanks in order to reduce to a minimum thetendency of the end bar to tear out. Other objects will appear from timeto time in the course of the specication e and claims.

l illustrate my invention more or less diagrammatically in theaccompanying drawings, wherein- Figure l is a plan View of the strip ofmaterial operated upon; illustrating the eftectot the successive dieimpacts;

Figure 2 is a section along the line 2 2 of Figure l; f

Figure 3 is a plan view similar to Figure l, but showing the under sideof the stock;

Figure d is a skeleton side elevation of the punch and die, illustratingthe passage of the stock therethrough, and vits .formation into links;

Figure 5 is a View of a rounded punch which may be substituted for thepointed punches shown in Figure 4; and

Figure 6 is a longitudinal vertical section through aslightly modiliedform of punch and die; l

Figure 7 is a plan View of the die structure. f Y Y l p l Like partsareillustrated by like characters throughout the specification anddrawings.

A is any suitable base having mounted thereupon the die block A1 whichmay be secured thereto in any suitable fashion.

B is any suitable strip of relatively resistant material upon whichrests the individual die elements. These elements are gripped andaligned in any suitable manner and will later be discussed in detail.

rlhe passage of the metal strip C over the die block is from right toleft, as shown in Figure 4. This ribbon or strip of stock C maybe'initially straightened and fed by any suitable means not hereinshown, being guided into the machine for example by the yieldinglymounted supporting block C1, Which is mounted to reciprocate verticallyin the die block A1, being supported; for example by the spiral springC2, its vertical movement being limited in any suitable yfashion. C5 isa centrally disposed iiat bearing surface thereon, adapted to receivethe bottom of the strip C and upon Which the strip may be centered, forexample by a pair 01" opposed set screws CG, which may be adjusted toadjust the strip C laterally.

D is a second strip or stock supporting yoke or block slidable alongvertical pins D2 and upwardly pressed by the spiral springs D3 againstthe heads D4 of the pins.

P, P are conical prick punch elements mounted in the yoke D, the purposeof which Will'be later described.

Positioned to the left of the support D, as shown in Figure 4, are apair of opposed strip or stock guiding elements E adapted to reciprocatein the apertures El in the block A1, the lower portion of each servingas a plunger to guide this reciprocation They are normally maintained ina position of maximum elevation by the coiled springs E5 Which penetratethe cylindricalapertures E@ in the guide elements. The upper por- Ytrionofv the guide elements are laterally inwardly slotted to engage the edgeof the stock or strip which may be centered between the opposed guides,for example by the set screws E"a k u is. astocv V,en agingelement havina pair of` ilpii'ardly rojecting, longitudinglly extending iugs G1, Gladapted to engage the side bars of the lilik blank. It rests upon thetops of a pair of plungers G2, the lower extremities of which are fixedin a yoke Gr8 slidable along the pin G4. Gr"I ris a spiral springcompressed between the yoke G3 and the stock G adjacent the lowerextremityof the pin. G7, G7 are adjusting nuts screw threaded upon thelower portion Gs of the in. i y y Mounted still farther tothe left, asshown in Figure 4, are a pair of opposed channel ironhguides H, H,adaptedto engage the o posite sides of the chain links. `Any suita emeans may be provided for drawing them forwardly therealong, said meansbeing not shown herein, and forming no part of the invention,u claimedvin ,the present application,l The channels H are connecte' for example,by cross pieces H1, the ends of whichare perforated to slide upontllegpairs of vertical guides H2, and are kept normally in raisedposition, as shown in Figure ,4 by the spiralqspringsyH?. The heads Hiof the `pins serve, as stops to limit the upward movement of thecrosspiece H1.

The chain formedvby the passage between the opposed die and punchelements of a strip of stock which is moved forwardly therebetweenby astep by step movement, bywany suitablefeeding means, the details (ifwhichneed not be shown herein. At ea vh successive vforward movement thepunch e ementdis moved downwardly againstv the die element byy anysuitable press mechanism. The punch block K is clamped into any suit;-ablelworki backing Kt, for example by the set Screws ll. K7 is a backingor base element similar to the backing orbase B of the Vdie block, andada ted to engage the inner endswof the indivi( ual punch elements. MTheunch and die elements are for` purposes oA description arbitrarilygrouped into the membersor areas operating simultaneously upon the linkblank as it passes step by `step therebetweem and will be described inrelation to the impression they successively make upon the blank. As thestock C is assed lforwardly through the guide C1 it is :t engaged byopposed indented or striated gripping pads L, L1, L being fixed inrelationy to the die block A1, L1 being yieldmounted in the punch blockK, and hield in normally downwardly extende po'siti'o .for example, bythe spiral spring L The unctionof the opposed pads is to grip thestockand prevent lateral movement thereof during and in response to thesuccessive forming impacts, their action being particularly importantwhen the strip is first fed through between the punch and die and beforeits end has reached the opposite end of the die. The pads ma be ofmetal, orrof any suitable fibrous or rictionf length of one chain linkblank, and is then 'Y subjected to the action of a pair of prick punchesL2, L2 on the die, and a transverse scoring knife L3 on the punch. ri`heprick piiiich elements are so positioned as to indent the innercorncrsof the junctions .y

between lthe side barsand the pintel 'en-d bar, en the'iowerI side ofthe stock along the line of future division between the tongueshwhicliwill ultimately be separated fromtheside bar to form the hoo pintleofthe lcomp eted link.

44WhereasIH prefer to use sharp pointed prick puncheshit will beunderstood hat undery some ircumstances a rounded or lall tippedpuncibor indentinl instrument can be/,substituted which wil have the sainefunction and perform the same service. The alternativetype of prickpunch is illustrated as P in Figure `5. e I

the next forward Amovement of the sto "Y they blank or future link is soositionedthat transverse severing kni e L5 oyerlies the score Z3 andsevers the metal therealonff, cuttin apart the edges of the o posed,fook an pmtle tongues, bending t e pinte tongue` downwardly about theEend LMand slightl bending the end of the ook tongue and 4eginning itsseparation from `the side bars, as shown in Figure 2.

Meanwhile, the yopposedpairs of longitudinal scoringknives L, LT scoreor outline the unsevered or uncut edge of the hook tongue on vthe topand bottom of the stock respectively, as shown at Z7 in Figure 1 and Zin Fi ure. 3. n u b At t e next forward movement of the stock it passesabove the yielding block D, above described, and the bottom ofthe stockis punched by the prick punch elements D thereupon, the prick punchmarks coming at thecnds of the bottom longitudinal scores l andindicating the inner corners of the junction between the side bars andthe hook end bar of the link. The punch inarkfs'sbve to prevent tearingout of the stock when the hook tongue is severed from the side barsalong the longitudinal scores l", Z7.

The knife L1l further bends the ends'of the pintle and hook tongjies,thel eiidbf tlie plintle tongue being bent about the beading e l" andthe end of the hook tongue being rolled about tl'ie rounded corner L1*of the yieldingly mounted block D. The hook tongue is thereby separatedfrom the side and i Cru bars along part of the length of thelongitudinal scores l, Z7.

At the next forward movement kof the stock the punch element L16completes the separation of the hook tongue from the side bars, movingit to the position shown at X15 in Figure 2, the punch marks llopreventing tearing away of the hook tongue at the corners. Meanwhile thetransverse` scoring knife L20 deeply scores theV top of the stock,outlining the separation between adjacent links, and the end of thepunch element L16 further slightly bends the pintle tongue about thetransverse bead L18, along the left l edge of theblock D, as shown inFigure 4.

At the next forward movement of the stock the punch element M which hassubstantially the cross section of the central aperture of the link,punches out or moves -v the hook tongue to the position shown at m1 inFigure 2. Along the base of the punch M are the inclined punch ledges l2 adapted to engage the side bars of the link and bend them into theposition shown at m3 in Figure 2. The rounded ends M4, M5 of the base ofthe punch block M, operating against corresponding die elements, bendthe hook and pintle end bars respectively of the link to the form shownat m5, m7 in Figure 2.

T he punch M near the pintle end is slightly wider, as at M9 than thecentral aperture of the link, and chisels out a part of the aperture toallow freedom for the hook in the finished chain.

Finally at the next movement of the stock the cutting edge N, formed bya downward off-setting of the punch, shears along the score 220 andagainst the opposed cutting edge N1 of the die, and severs the partlycompleted link from the stock. As the stock is forced down bythe punch,prior to the severing, the side bars of the linkare engaged by thelongitudinal lugs G1 of the yieldingly mounted block G, and are lockedthereby against the punch element N2, which is provided with a centralportion N3 penetrating within the central aperture of the link, and sidebearing surfaces N4D in opposition to the tops of the lugs G1. Thesevered link is thus firmly gripped, the spring G5 serving to compressthe block G and the lugs Gl against the link, and to lock the linkagainst the punch N2.

The curved portions N5, N6 of the punch i" N2 engage respectively thebent hook and pintle end bars. As the link is carried downwardly by thepunch, the end of the hook tongue engages the rolling die surface 1 N5and is curved thereby into the position N7, as shown in Figure 4. Priorto the com- `pletion of this rolling movement the pintle tongue contactsthe die surface NS and is bent into the position shown in Figure 4;. Therolling movement of the hook tongue is shown at O in Figure 4. The hooktongue t curls around and incloses it, thus fastening thenewly formedlink to the end of the completed chain, as shown in dotted lines at O1in Figure A.

The guides H and the completed chain y travelling therethrough arenormally maintained in general alignment, as in Figure l, with the stockas it passes throuoh the yieldingly supported guide elements (ril and E.As the stock is depressed by the action of the punch elements thereupon,the punch also contacts the cross elements H1, and depresses thefinished chain, maintaining it in alignment with the stock as itdescends and with the descending severedlink as it continues its descentfollowing severance from the stock. As the hook tongue of the linkbegins to curl, as at N7, the pintle bar of the finished link is droppedinto position in the bend of the hook tongue and is thus sur- .7;

roundedby it as the hook tongue is rolled into final position. At thenext forward movement of the stock and the completed chain, thecompleted link is drawn forward with the completed pintle bar ready lquent breaking down and weakening of its I structure, I provide at eaclrside of the scoring knife T the depressions T1, T1. The scoring orcreasing knife T2 serves to crease the bottom of the stock along theinside of the bend of the future pintle tongue. The prick punch elementsL2 are shown as moved forward one step to Voccupy the position of thepad L in Figure e, and the pad L may be moved forward, or may, ifdesired, be dispensed with.

The use and operation of my invention are as follows: j

I manufacture chain from a ribbon or strip of sheet metal stock which isfed forwardly step by step between opposed punches Y and dies. Theinterval between the forward feeding movement needv be only suiiicientto permit the strip to move forwardly through the press the length ofone link.

In order to prevent interference between the stock and tlie punch ordie, at the time of Stich forward iriov'einent, I provide means forlifting the enen-e snip of stock from the die between the formingimpacts of `punch upon die. In the form herein shown,

move the strip upwardly, after each impact, to a. position substantiallymidway beween puneh and die when the punch is `i'ivithdravvn to itsmaximum Height. In the illustrated mechanism, I accomplish this re-'siit by feeding tlie strip forwardly through yieldingly mounted guideswhich are adapted normally to su )port the stock a predetermineddistance .f ove the dies, but which ermit it to descend, and descendwith it, in response to the action of the punch. As the punch descends,it forces the strip and with it the strip guides downwardly toward thedie block, and as soon as the punch withdraws, the guides rise and carrythe strip with them. I center the strip in relation to die and punch bymeans of setscrewsor other adjusting mechanisms on the yieldin lymounted guides or supports.

n the form of punch and die herein shown, the portions which are forcedout of the normal plane of the strip are allbent downwardly toward thedie. It is there- 'fore necessary to lift the strip above the `die adistance greater than the length of the lar est downward projection,namely the hoo tongue. In the method of forming chain herein described,the side bars of the chain are not deformed or bent until shortly beforethe link is severed from the chain stock. Therefore the stock throughoutmost of its excursion between the punch and die has straight edges, andcan easily and eiliciently be fed forwardly through the guides.

The stri metal stock, of which the links are forme is a. fibrousmaterial, and of course tough and hard. In making links from it it isnecessary not only to render easy the severingof the parts which have tobe severed, and to make this severing possible without distortion of thestock, but also to limit the severing and to counteract the tendency forfurther and unintended tearing or severing, either during manufacture orduring later use of the chain. To lhke the severing easy, the parts tobe severed are initially scored. Toprevent further unintended tearingthe lines of score are terminated by indentations which break up thenormal fibrous structure of the material. The major severing operationsare performed, not by one impact, but by a succession of impacts. Thedistortion of the metal at any one point is reduced to a minimum, andsharp bends, or corners, where tli'e material of the stock is compressedby bending, are provided with creases or indentations which serve togive space for the material compressed, for example along the pintletongue and at the corners of pintle and hook tongues, where they arebent from' the stock. y

Tlie'successive steps of the operation are as' fellows:

1. The gripping step, the action of the opposed gripping pads, one fixedand one yielding, one on the punch and one on the die. These opposedpads grip the metal stock and prevent its longitudinal movement. Theiraction is important primaril during the initial feed of the stockthrough the press, and the chain forming process ma be carried onwithout them, although un er many conditions they are valuable.

2. The center of the link is next transversely scored as at Z3 tooutline the separation between the opposed edges of hook and pintletongues. shown this score is across the top of the stock, but of coursethe location of this and ofthe other score and punch marks hereindescribed could be inverted. The opposite side of the ystock is indentedas at Z2, Z2, the punch marks indicating the corners of the uturecentral aperture of the link, and breaking up the regular fibrousstructure of the meta-l at those points.

3. As the strip moves forwardly one step, the same area is next operatedupon by the opposed scoring knives Z, Z7 which outline, upon the top andbottom of the link, the eparation between hook tongue and the side ZIS.the transverse score Z3, but this is not necessary, since the transversesevering knife Z5 at the same time severs the stock along the scoreZsahd bends back the pintle tongue and the end of the hook tongue, thescores Z6, Z7

reachin substantially to the point at which the hoo` tongue is separatedfrom the side bars. The "intle tongue is bent about the bead L?, wiiichmakes a transverse crease alonthe inside of the bend, and connects y;

the original separation between iook and pintle tongues. One side ofthis element further bends the pintle tongue, and bends it about a beadZ, which further enlarges the rrooveror crease Valong the inside of itsbend.

he other side further bends the end of the hook tongue continuing itsseparation from the sidebars, and gives to its end a curve,substantially concentric with the future arc *of the finished hook.Meanwhile the bottom of the stock is punched as at Zw, Z1", the

In the mechanism herein These scores do not extend as far as ;l

punch marks closing the ends of the scores Z6, and serving to preventthe tendency of the link to tear out when the hook tongue is nally bentaway from the stock.

5. At the next forward movement of the stock the hook tonvue is operatedupon by a punch element which completes its severance from the link sidebars and bends it to the position X16 in Figure 2. The previously madeindentations Z1", which have broken up the fibrous structure of thecorners of the link, prevent weakness and tearing at the base of thehook tongue.

6. At the next forward movement of the stock .the downwardly dependingpintle tongue drops over the corners of the die element m20, andprevents longitudinal dis-v tortion of the entire strip to the rear ofthe point, or shortening of the strip or of the individual links by theimpact and distortion action of the forming punches.

Up to this point the sides of the stock have been straight, since therehas been no distortion of the side bars. Now, however, the line ofseparation of the two adjacent links is made along the score Z2() andthe link thus separated, is bent to the position shown at the left endof the Figure 2. Meanwhile the hook andV pintle bars are bent vinto theposition shown at m5, m7 and the central aperture ofthe link adjacentthe pintle bar is slightly widened as at m9.

7. The link is now ready to be severed from the stock and at'its neXt.forward movement it is sheared along the score Z2 and is carrieddownwardly bythe punch element n2 toward the lower forming die. The hooktongue m1, since it depends farther from the link than the pintletongue, is the first to Vcontact .the die and is rolled around by thesemi-cylindrical die surface ne into the form shown at a7 in Figure 1l.W'hen the link has beenk carried so far down that the pintle tongue alsocontacts the die, it is bent into finished form. Since it is bent orcompressed far more highly than the longer Ahook tongue, the creases orgrooves along the inside of the bend of the pintle tongue are extremelyimportant in preventing weakening of the pintle tongue, and the punchmarks at the corners are vital in preventing strain upon and distortionof the metal at those points.

The pintle of the precedingly completed link is positioned within thearc of the hook tongue as it is beingcurled into final form, and ittherefore curls about the pintle and passes through the central apertureof the preceding link. The pintle endof the link being somewhat widened,as at m9, there is ample room for the hook tongue to pass therethrough.The 'link thus completed is drawn forwardly away from the end of theStock and at the next movement ofthe stock the succeeding link is fedforward ready for separation and nal formation.

In the form shown in Figure 6 I have illustrated a means for minimizingthe effect of the transverse scoring knife in breaking up and weakeningthe structure of the metal. I provide an opposed scoring knife justsufiicient to break the surface of the lower side of the stock, and Iposition it between transverse indentations T1 which give space for themetal displaced by the scoring knife L3. Strain upon the metal is so fareliminated as to prevent any appreciable weakening of the fibrousstructure of the future link. I also indicate in Figure 6 the creasingelement T2 which scores or creases the inside .of the bend of the futurepintle tongue, making easier its bending and enabling it to be bent witha substantially reduced strain upon and weakening of the brous structureof the metal. I may dispense with the prick punches, or I may move thema step forward on the die, as shown in Figure 6. c

While I have illustrated an adequate and operative device, and apractical and efiicient process, it will be realized that I do not wishto be limited to the speciiic details and steps shown, or to thespecific order of steps'. I wish my description to be taken rather as inabroad sense diagrammatic, and illustrative, since many changes in formand arrangement of steps and the parts used to accomplish the steps maybe made without departing from the spirit of my invention.

I claim:

1.*'Ihe process of making chain from a continuous strip of sheet metalstock, which consists in scoring said stock to outline the inner edgesof the side bars of the links, severing the metal between said scoresand progressively separating a tongue of metal within said scores fromthe side bars, along the lines of score, by successive impacts upon thetongue, and maintaining the end bars undeform'ed and in the plane of thestock during such impacts until after the separation of the tongue fromthe side bars is completed.

2. The process of making, from a continuous strip of sheet metal stock,chain comprising links having pintles and hooks struck from the centerof the link blank, which consists in first transversely scoring thecentralportion of the stock prior to the operation thereon of anyforming or severing memllO bers;Y then longitudinally sco-ring the stockto Voutline the inner edges of the side bars and separating the opposedends of hook and pintle tongue along the transverse score, and rollingthem apart in like direction away from the plane of the stock; thenseparating the hook tongue from the side bars along the line of score;and finally severing the blank from the stock and rolling the hooktongue about the pintle of the neigt preceding link; and maintaining theside and end bars of the link blanks flat and unextended until theseparation of the hook and intle forming tongues from the side bars 1scompleted.

3. The process of making, from a continuous stri of sheet metal stock,chain comprising lin s having pintles and hooks struck from the lcenterof the link blank, which consists in first transversely scoring thecentral portion of said stock; then longitudinally scoring the stock tooutline the inner edges of the side bars of the links and tearing apartthe op osed ends of hook and pintle tongues, an rolling them apart alongsaid transverse score in like direction from. the plane of the stock;then bending the outer end of the hook tongue into substantially arcuatecross section; then downwardly bending the hook tongue and completingits se aration from the side bars; then further ending the hook tonguefrom the side bars and bending the entire blank downwardl. from thehitherto unbent stock.

4. he process of making, from a continuous stri of sheet metal stock,chain comprising lin s having pintles and hooks struck from the centerof the link blank, which consists in longitudinally scoring the stock tooutline the inner edges of the side bars, and severing the metal betweensaid longitudinal scores; then indenting said stock ad- 'aent thejunction of the side bars and the ook end bar toward which the tonguesare to be bent, and separating the hook and pintle tongues from the sidebars, by bending them in the direction of the indented side of thestock.

5. The process of making, from a continuons stri of sheet metal stock,chain comprising lin having pintles and hooks struck from the center ofthe link blank, which consists in indenting the blank adjacent the'uoton of the side bars and the pintle end ai, longitudinally scoringthe stock to outline the inner ed es of the side bars, severing themetal etween said longitudinal scores, indenting the stock adjacent thejunction of the side bars and the hook end bar, and separating the hookand pintle tongues from the side bars by bending them in the directionof the indented side of the stock.

6. The process of making, from a continuous strip of sheet metal stock,chain cornliisillg links having pintles and hooks struck from the centerof the link blank, which consists in indenting the blank adjacent theinside corners of the junctions of the kside barsY and the end bars,longiudinelly scoring' the stock to outline the inner edges of the sidebars, severing the metal between Said longitudinal scores, and separatithe hook and pintle tongues from the s' y e bars by bending them in thedirection of the indented side of the stock which consists in indentingthe stock at the junction of the side bars and the pintle end bar andtransversely scoring the central portion of the stock to outline theabutting edges of the hook` and intle forming ton ues; then longitudinaly scoring thc stoc to outline the inner edges of the link side bars;then separating the hook and pintle tongues from each other; thenindenting the stock at the junction of the side bars and the hook endbar on the same side Y of the blank as the previous indentation, andbending the hook and pintle tongues in the direction of the indentedside of the stock.

8. The process of making, from a continuous strip of sheet metal stock,chain comprising links having hooks and pintles struck from the centerof the link blank, which consists in first indenting the blank adjacentthe intersection of the side bars and the intle bar, and transverselyscoring the blan then longitudinally scoring the stock to define theinner edges of the side bars, and transversely severing the stockbetween such scores, and creasing and bending the pintle tongue andbending the outerl end of the hook tongue; then further bending thepintle tongue and bending and forming the outer end of the hook tongueto conform substantially to the arc of the latter 'l formed hook,indenting the blank adjacent the intersection of the side bars and thehook end bar, and beginning the separation of the hook tongue from theside link bars along the lines of score; then further creas- 3..

ing the pintle end bar and bending the pintle tongue substantially atright angles to the stock and at the same time shearing the hook tonguefrom the side bars along the lines of longitudinal score, and bending itat a substantial angle to the stock; then transverselyscoring the stockalon the line of separat1on of the adjacent blan is and at the Vsametime crimping the hook end bar, the

ends of the side bars and the pintle bar, and bending the entire blankto a slight angle in rela tion to the hitherto Hat stock; then shear ingod the blank and bending the pintle toue into final position and rollingthe h tongue substantially cylindrically bout dthe pintle of the linkpreviously orme 9. The process of making from a continuous strip Vofsheet metal stock, chain comprisi g links having pintles and hooks lil)from the stock, and opposing said tongue to one of the die elements toprevent longitudinal slipping oi the stock at the moment of impact ofopposed punch and die'.

10. rEhe process of making, froma con tinuous strip ot sheet metalstock, chain comprising links having pintles and hooks struck from thecenter of the link blank,

,which consists in outlining opposed hook and pintle forming tongues,separating them Jfrom each other, and completing their separation fromthe side bars, unextended, and crimping the hook and pintle end bars outof the plane of the side bars, and bending the link blank at an angle tothe stock, in the direction in which the tongues had previously beenbent.

11. The process of making, from a continuous strip of sheet metal stock,chain comprising links having pintles and hooks struck from the centerot the link blank, which consists in outlining opposed hook and pintleforming tongues, separating them from each other, and completing theirseparation from the side bars while maintaining the side' and end barsof the link blanks liat and unextended; bending the hook and pintle endbars out of the plane of the side bars after the separation of saidtongues from the side bars, and bending the link blank at an angle tothe stock, in the directi .l in which the tongues had previously beenbent; and then severing the blank, bending thepintle tongue into iinalshape, and rolling the hook tongue about the pintle oi the previouslycompleted link.

12. The process ot making, from a con-v tinuous strip of sheet metalstock, chain comprising links -iaving lpintles and hooks struck trom thecenter. of the link blank, which consists in transversely scoring thecenter ci tne link blank; then'severing the l along such score, bendingthe pintle tongue, while creasing `the inside of its bend, and bendingthe end oi the hook tongue; then further bending the pint-le tongue,iurther bending' the end of the hook tongue; and beginning itsseparation romthe side bars; then further bending the pintle tongue andcompleting the separation of the hook e from the side bars. Y. Theprocess of making, from a continuous strip ci" sheet metal stock, chaincomprising links having pintles and hooks uck from the center of thelink blank, wnich consists in indenting the inner corners oit theintersections of the side bars the ci l bars or the blank, severing thehook and pintle tongues from each other and from the e bars, and bendingthem away irointhe e bars in the direction oi the indented ot the blank,and bending the hook igne about the pintle of the precedingly completedlink.

14. rlhe process .of making, from a continuous strip .of sheet metalstock, chain comprising links having .pintles and hooks struck from thecenter of the link blank, which consists in passing said stockJforwardlybetween opposed punch and die elements, liiting` said stockfrom said guide ait-er each forming impact and supporting said stockbetween and out of contact with said punchY and die elements between theforming impacts at a plurality of points longitudinally opposed alongsaid stock, and feeding said stock forward while so supported.

15. The process of making, from a contin uous strip of sheet metalstock, chain coniprising links having pintles and hooks struck from thecenter of the link blank, which consists in passing said stock forwardlybetween opposed punch and die elements, and subjecting each linksuccessively to .their forming action, severing the link from the stock'prior to completing the rolling up oi the hook tongue, carrying saidlink downwardly below the plane of the die, positioning the chain withthe pintle of the link last completed within the periphery of the arc tobe described by the hook tongue in course of its formation, carryingsaid completed link downwardly in unison with the descent of said link,and curling said hook tongue about the rpintle of said link in responseto the downward movement of said hook tongue against a forming die.

16. The process of making, from a continuous strip of sheet metal stock,chain comprising links having pintles and hooks struck from the centerof the link blank, which consists in transversely scoring the centralportion of said stock to outline the separation between the hook andpintle tongues and at the same time transversely scoring the inside oithe bend of the 'future pintle tongue; then longitudinally scoring thestock to outline the inner edges of the side bars, and severing themetal between said longitudinal scores along said trans verse score;then separating the hook tongue from the side bars along the lines oi"Ascore.

17. The process of making, from a continuous strip of sheet metal stock,chain comprising links having pintles and hooks struck from the centerof the link blank, which consists in passing said stock Jforwardlybetween opposed punch and die elements in a step by step movement,engaging the edges of the stock and liitingsaid stock to a positionbetween and outof contact with said punch and die elements, between theforin-l lill 8 1,7es,ss2

struck from the center of the link blank, which consists in passing saidstock forwardly between opposed punch and die elements in a step by stepmovement, engaging the edges of the stock at a plurality of ointslongitudinally spaced there along, an lifting said stock to a positionbetween and out of contact with said punch and die elements, between theforming impacts, feeding said l stock forward one step, between eachforming impact, while so supported and holding it against lateralmovement and maintaining the edges of the stock substantially unbent and1n substantially the same plane L., until after the hook and pintletongues have been completely separated from the side bars of the link.

Signed at Chicago, county of Cook and State of Illinois, this 29th dayof April,

RAYMOND W. DULL.

